Generally, critical components of machines may be cooled using cryogenic systems. In such systems, a cryogenic fluid is used to cool the components in which temperature is controlled by allowing the cryogenic fluid to boil and vaporize at a saturation temperature. In some systems, the same cryogenic fluid may then be required to cool another downstream component or may be stored. In some situations, the downstream component or the storage may require the cryogenic fluid to be in liquid state due to process requirements. In such a situation, the vaporized cryogenic fluid may need to be cooled and converted to liquid state before reaching the downstream component or being stored. This in turn requires additional systems to cool the vaporized cryogenic fluid increasing system cost, maintenance cost and/or lowering system efficiency. Also, a flow rate of the cryogenic fluid may have to be accurately controlled for providing desired temperate control of the components. As a result, additional flow control systems may have to be employed in the system increasing system and/or maintenance cost.
U.S. Pat. No. 7,054,764 describes a method of determining a flow rate of a fluid having a liquid fraction and a gas fraction. The method includes measuring a pressure and temperature of the fluid at a flow control device through which the fluid passes. The method includes inputting the measured pressure and flow coefficient (Cv) into an algorithm. The method also includes performing a single or multi-step iteration to determine a fluid mass flow rate of the fluid through the flow control device using the algorithm. The algorithm relates the mass flow rate of the fluid to the Cv, and mass densities of the liquid fraction and the gas fraction of the fluid which are a function of the measured pressure and temperature.
Some flow control systems measure the flow rate of the cryogenic fluid before and after the cooled component. However, such systems may require high accuracy cryogenically compatible equipment and a controller to accurately control the flow of the cryogenic fluid. Hence, there is a need for an improved system and method for controlling the flow of the cryogenic fluid.